1. Technical Field
The present invention relates to a solder injection head.
2. Description of the Related Art
Bumps may be formed on a substrate in order to mount electronic components on the substrate. Examples of a typical method of forming the bump include a solder paste printing method, a solder ball mounting method, and a melted solder injection method. The solder paste printing method is a method in which a solder paste is printed on the substrate and a reflow is performed on the solder paste. The solder ball mounting method is a method in which a fine solder ball is directly mounted on the substrate. The melted solder injection method is a method in which a melted solder is directly injected onto the substrate or injected onto the substrate using a mask. In an apparatus for directly injecting the melted solder, as disclosed in U.S. Pat. No. 6,231,333, all solders are stored in the melted state in the solder injection apparatus. In this case, the melted solders may be left in the solder injection apparatus for a long period of time. In the case in which the solders are left in the melted state for a long period of time, the solders are oxidized, such that it is difficult to form a reliable bump later.